The Apollo 11 command module was equipped with a small (5 x 4 inches) battery-powered voice recorder to record data and observations during the mission. The recording element is a tape cassette. At launch the voice recorder was stowed with a battery and a cassette installed. Several replacement batteries were provided. This is one of four replacement batteries returned from the mission. It was transferred to the Smithsonian in 1971.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.